Method of treating leather



Patented Jan. 21, 1936 umrso STATES PATENT. OFFICE BEN RUBENS, 0F LOS ANGELES, CALIFORNIA, ASSIGNOR 0F ONE-FIFTH TO ARTHUR BRICK, ONE-EIGHTH T0 WILLIAM HALL1\TER, ONE-EIGHTH TO ISIDORE PRITSKER, ONE-EIGHTH TO SAM KAGAN, ONE-EIGHTH TO NORMAN L. COHEN, AND ONE- FORTIETH TO SAMUEL HOROWITZ, ALL DE LOS ANGELES, CALIFORNIA METHOD OF TREATING LEATHER A No Drawing,

This invention relates to a process and method of molding leather articles into de sired shapes. Specifically, the invention is applicable to the molding of shoes, although footballs and bags of various forms may be readily made by the method to be detailed.

Considering at this time the making of shoes, it might be said that in order to produce an ordinary pair of Oxfords some thirtysix machines are employed. Furthermore, it takes from five to twelve days to completely finish a pair of shoes. \Vith the process and method to be described the longest period of time required to produce a pair of shoes" would be twenty-four hours, at which time they would be ready for the market. Briefly stated, I might form a shoe by saturating the leather with a chemical, placing an inner sole on the last, then molding the leather around the last and allowing it to set, cement the welt to the insole, next pasting the sole on the welt, stitching the sole and welt, cementing on the heels, then cutting the upper of the shoe from the lower ball around both ankles, and utilizing the piece which comes from the top thus cut away for the tongue of the shoe. The present method is economical in actual prac tice, for the reason that the dipping or sponging step in treating the leather allows the leather to set sufiiciently in a few minutes of time, whereas inthe past it has taken some twenty-four hours for the leather to properly set, and thus many pairs of shoes will be released which would otherwise be impounded.

I do not particularly claim a one-piece shoe, but I do claim that the method and process which I utilize is capable of producing better results in a more efiicient manner than is now accomplished, so far as I am aware.

An object of the present invention is the provision of a process and method of treating leather which renders the leather moldable, and which does not affect in any way the color or strength of the leather.

Another object is the provision of a method and process of treating leather which permits the leather to be readily moldable to a given form, and after it is so molded it will set quickly, and when it does so set it Wlll retain such molded form.

1927. Serial N0. 187,119;

-Other objects will appear as the specification proceeds.

I have formed various articles in accordance with my invention, and in the case of shoes I have found that the shoes stand up under the most severe tests, at all times retaining their shape and form, without stretch. As a matter of fact, I have been able to make a pair of shoes by hand in half a day.

I have discovered that various ingredients may be combined for treating the leather after the leather has been tanned, which will render the leather pliable enough to permit-of its being molded to a given shape on a mold. However, quite a number of said chemicals are detrimental to the leather. I refer articularly to the use of alcohol, which tends to tion that I have found best suited to my needs consists in utilizing five parts by weight of ground tan bark, with ninety-five parts of boiling water, and stirring this solution for several minutes, after which it is filtered through a fine'mesh cloth. I then add a onelength between marks'of 1 and 25/100 inches, I

and loaded with a 16 lb. weight for half a minute, with my solution the elongation of the treated leather While wet Was 52 per cent, and when released the elongation was 20 per cent, and when dried and free of the weight the elongation was 12 percent. Practically the same results were obtained with specimens of brown calf of the same dimensions.

Utilizing natural color sheepskin I found that the breaking strength in pounds per inch width of the untreated leather ran 48, while leather treated with my solution ran 80. Brown calfskin, untreated, was over 200, and with my solution 216. Black calfskin, untreated, was 168, and with my solution 200. It would therefore appear that the treated leather has a greater breaking strength than untreated leather.

Leather treated in accordance with my solution will be found to be firm and well shaped,

without being at all stiff, when the leather is dry.

The following will show the results of some of the tests made with different solutions: #1. 4% caustic soda in watcr.Slight spot at point where number was penciled. Otherwise condition good but not entirely uniform; color slightly lighter and luster not so good as original.

#1A. caustic soda in watcr.No spots, uniformly good, luster very little decreased, color better than' #1.

#2. Rubens sotation. 4% caustic soda with water extract from 5% oak tan bar7c.- No spots, color and luster almost same as original, uniformly good. Firm and well shaped without being stiff.

#3. 4% caustic soda, 10% alcohol, in water.Spotted where penciled. Lighter colored, morewrinkled, and not v as well shaped as samples above.

#4. 4% caustic soda, 20% alcohol, in

-wate1'.-Color uniformly poor, spotted and wrinkled.

#5. 4% caustic soda, 10% alcohol, with water extract from 5% oak tan bark-Genera1 appearance and uniformly good, color liglliter'and luster inferior to #2. Shaped we #6. Woiter.Badly wrinkled, limp, not well shaped. Color and luster good but had appearance of weakness.

#7. D1'g .'N0 shaping, 'flabby, wrinkled, color lightened in parts most stretched.

It is no doubt evident from the description as so far given that the only requirements in practising the invention would be a solution plus a mold over which the treated leather would be stretched to form and then allowed to set. As the solution dries very rapidly,

the leather could be removed from the mold within a few minutes of time. I do not wish to partlcularly confinethis invention to the manufacture of shoes,- although it is evident that shoes could be manufactured very rapidly by utilizing the present solution.

'Briefly, I might describe the operation of forming a shoe, which is as follows: I may take a piece of leather and dip it or sponge it in the solution, then take'an inner sole and fasten it to the last with a few tacks, so that the leather holds to the last. I then mold the on the inner sole, so that the sole and welt will hold together. I also may place a piece of steel on the bottom and then paste the sole on to the welt. The sole is then stitched with a machine, after which I cement the heels to the leather and finish the shoe in the usual manner. I then cut the upper of the shoe from the instep along both sides of the ankle portion, and the piece that comes out of the top is applied and cemented in front and used for the tongue, after which the eyelets are placed in the leather in the usual manner. The shoe after having the laces placed through the eyelets is then ready for use.

Leather gloves might be formed without the use of seams by stretching the leather over a mold, after the leather had been treated with my solution. In fact, the use of the solution is unlimited for the purpose intended.

It will be noted that in certain of the tests enumerated that reference is made to a point where a number was penciled. In this connection, I may state that after the leather has been saturated or sponged with my solution, I may then mark the leather with any design desired with an indelible pencil, and it has been found that when the leather is dry that thev solution has so aflected the indelible as to practically prevent its removal from the leather. Water does not affect the indelible, and the only liquid thatapparently removes it is alcohol.

The tan oak bark aids in preserving the leather by allowing the oils already in the leather to remain therein. 1

As I have previously stated, I may mold the leather to any desired form, and the in-' vention lends itself readily to the forming of leather trunks, valises, auto tops, and the like. The uses of the invention are so numerous that no particular article of manufacture will be described.

Having thus disclosed my invention, what I claim and desire to secure by Letters Patent is:

1. A solution for the treatment of leather to render the same pliable, comprising substantially 4% caustic soda with water.

2. A solution for treating leather to render the same pliable, comprising substantially 4% caustic soda and 5% oak tan bark.

3. The method of forming a solution for name to this specification.

to substantially parts of boiling water, stirring said solution, then filtering the solution, and finally adding to said solution so filtered substantially 4th part caustic soda, then allowing the solution to cool.

In testimony whereof, I have signed my BEN RUBENS. 

